Q. No.Given below are two statements:
Assertion (A):
Gauss's law for magnetism states that the net magnetic flux through any closed surface is zero.
Reason (R):
The magnetic monopoles do not exist. North and South poles occur in pairs, allowing vanishing net magnetic flux through the surface.
1.
(A) is True but (R) is False.
2.
(A) is False but (R) is True.
3.
Both (A) and (R) are True and (R) is the correct explanation of (A).
4.
Both (A) and (R) are True but (R) is not the correct explanation of (A).
| Statement I: | The magnetic field of a circular loop at very far away point on the axial line varies with distance as like that of a magnetic dipole. |
| Statement II: | The magnetic field due to magnetic dipole varies inversely with the square of the distance from the centre on the axial line. |
| 1. | Statement I is correct and Statement II is incorrect. |
| 2. | Statement I is incorrect and Statement II is correct. |
| 3. | Both Statement I and Statement II are correct. |
| 4. | Both Statement I and Statement II are incorrect. |
1. negative
2. zero
3. positive
4. infinity
| 1. |  |
2. |  |
| 3. |  |
4. |  |
Figure shows the graph for magnetic hysteresis for a ferromagnetic materail. From the graph, magnetic retentivity for the material is-
1. 2.5 T
2. 1.2 T
3. 1 T
4. 4 T
A domain in ferromagnetic iron is in the form of a cube of side length \(1~\mu\text m.\) The maximum possible dipole moment is:
[The molecular mass of iron is \(55~\text{g/mole}\) and its density is \(7.9~\text{g/cm}^3.\) Assume that each iron atom has a dipole moment of \(9.27\times 10^{-24}~\text{Am}^2\)]
1. \(8.0\times10^{-13}~\text{Am}^2\)
2. \(8.0\times10^{-12}~\text{Am}^2\)
3. \(7.0\times10^{-13}~\text{Am}^2\)
4. \(7.0\times10^{-12}~\text{Am}^2\)
A solenoid has a core of material with relative permeability \(400\). The windings of the solenoid are insulated from the core and carry a current of \(2~\text{A}\). If the number of turns is \(1000\) per metre, the magnetization, \(M\) is:
| 1. | \(8\times10^{5}~\text{A/m}\) | 2. | \(6\times10^{5}~\text{A/m}\) |
| 3. | \(6.5\times10^{5}~\text{A/m}\) | 4. | \(8.9\times10^{5}~\text{A/m}\) |
A solenoid has a core of material with relative permeability \(400.\) The windings of the solenoid are insulated from the core and carry a current of \(2~\text{A}\). If the number of turns is \(1000\) per metre, the magnetising field \(B\) is:
| 1. | \(10~\text{T}\) | 2. | \(1~\text{T}\) |
| 3. | \(0.1~\text{T}\) | 4. | \(2~\text{T}\) |
A solenoid has a core of material with relative permeability \(400.\) The windings of the solenoid are insulated from the core and carry a current of \(2~\text A.\) If the number of turns is \(1000\) per metre, the magnetic field intensity \(H\) is:
1. \(2\times10^2~\text{A/m}\)
2. \(2\times10^3~\text{A/m}\)
3. \(2~\text{A/m}\)
4. \(20~\text{A/m}\)
In the magnetic meridian of a certain place, the horizontal component of the earth’s magnetic field is \(0.26~\text{G}\) and the dip angle is \(60^{\circ}\). The magnetic field of the earth at this location is:
1. \(0.25~\text{G}\)
2. \(0.20~\text{G}\)
3. \(0.35~\text{G}\)
4. \(0.52~\text{G}\)
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